Field of the Invention
The present disclosure relates to an image shake correction apparatus, and to an optical device using the same.
Description of the Related Art
Conventionally, an image shake correction apparatus has been proposed that is configured to prevent image shake that tends to be produced by hand shake during an imaging operation when using an optical device such as a digital camera or the like. For example, this image shake correction apparatus has a configuration for detecting an image shake condition using a detection means in relation to the lens barrel provided in the optical device, and displacing an image shake correction lens (or image capture element) in a shift configuration in a plane that is orthogonal to the optical axis based on the detection result. In this case, image shake can be eliminated by displacing the correction lens in a direction that absorbs the principal vibration in the plane orthogonal to the optical axis to correct a deviation in the image forming position resulting from image shake. The correction lens in this type of image shake correction apparatus is moved by use of an electromagnetic force configured to act between a coil and a magnet. Japanese Patent Application Laid-Open No. 2009-145771 discloses an image shake correction apparatus that uses three balls to determine a position of the correction lens in the optical axis direction, and disposes three springs that are inclined with reference to the diameter in order to bias the balls. Furthermore, the image shake correction apparatus includes a damping member to suppress the effect of resonance.
However, the image shake correction apparatus disclosed in Japanese Patent Application Laid-Open No. 2009-145771 is not designed so that the thrust generated by the coil and the magnet overcomes the pulling force of the spring in a direction perpendicular to the optical axis due to the fact that the spring is disposed in a configuration to pull in an inclined direction. This configuration leads to increase the size of the actuator that includes the coil and the magnet. In order to prevent an increase in the size of the actuator, it has been proposed for example to configure the direction of spring pull with reference to the direction of the optical axis and not the direction perpendicular to the optical axis. However, it is not possible to avoid a size increase of the diameter in this type of image shake correction apparatus when for example, three balls, three springs, and furthermore two damping members are all disposed in a plane that is perpendicular to the optical axis in a configuration to avoid mutual interference.